cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 12 results. Next

A232949 Number of n X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

1, 21, 1881, 685251, 1074244299, 7168373617095, 205030957086979647, 25121788915317351455997, 13201474923932116066095060171, 29758989052767328125373420316820645
Offset: 1

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Author

R. H. Hardin, Dec 02 2013

Keywords

Comments

Diagonal of A232955

Examples

			Some solutions for n=3
..0..2..0....0..1..0....0..1..0....0..1..0....0..2..0....0..0..1....0..1..3
..3..2..3....3..2..3....1..0..0....1..0..1....3..2..3....0..0..1....1..1..1
..2..3..2....3..1..0....0..0..2....2..3..1....3..2..0....0..1..0....0..0..1
		

A232950 Number of n X 3 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

9, 129, 1881, 27441, 400329, 5840289, 85202361, 1242993681, 18133691049, 264547403649, 3859408908441, 56303849204721, 821401284620169, 11983196174074209, 174819534903392121, 2550393846506436561
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Examples

			Some solutions for n=4:
..0..1..3....0..1..0....0..0..0....0..1..3....0..2..0....0..0..0....0..0..0
..0..2..3....3..2..0....0..1..0....1..1..3....0..1..3....2..2..2....2..0..0
..2..2..2....0..2..2....0..0..0....0..1..1....1..1..0....2..3..2....2..0..2
..0..2..3....3..2..3....2..0..0....0..1..1....3..1..3....3..3..2....0..0..2
		

Crossrefs

Column 3 of A232955.

Formula

Empirical: a(n) = 15*a(n-1) - 6*a(n-2).
Conjectures from Colin Barker, Oct 06 2018: (Start)
G.f.: 3*x*(3 - 2*x) / (1 - 15*x + 6*x^2).
a(n) = (2^(-1-n)*((15-sqrt(201))^n*(-3+sqrt(201)) + (3+sqrt(201))*(15+sqrt(201))^n)) / sqrt(201).
(End)

A232951 Number of n X 4 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

27, 771, 22971, 685251, 20442651, 609853251, 18193384251, 542752261251, 16191600916251, 483034266181251, 14410069980856251, 429886928094781251, 12824557492939156251, 382587290147700781251, 11413495916966327656251
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Examples

			Some solutions for n=3:
..0..0..0..1....0..2..3..1....0..2..3..2....0..0..1..1....0..2..2..2
..0..0..0..2....0..1..0..2....0..2..3..2....2..0..1..3....3..2..2..2
..0..0..0..1....0..2..3..2....0..2..3..1....1..3..2..0....0..2..0..0
		

Crossrefs

Column 4 of A232955.

Formula

Empirical: a(n) = 31*a(n-1) - 35*a(n-2) + 5*a(n-3).
Conjectures from Colin Barker, Oct 06 2018: (Start)
G.f.: 3*x*(9 - 22*x + 5*x^2) / ((1 - x)*(1 - 30*x + 5*x^2)).
a(n) = (55 + (15-2*sqrt(55))^n*(55+sqrt(55)) - (-55+sqrt(55))*(15+2*sqrt(55))^n)/55.
(End)

A232952 Number of nX5 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

81, 4629, 283131, 17429409, 1074244299, 66226131273, 4082986991091, 251727862281441, 15519780149309307, 956841601733733945, 58992197961597648195, 3637048689898637056977, 224235130894279830031179
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Comments

Column 5 of A232955

Examples

			Some solutions for n=2
..0..0..2..2..0....0..1..3..1..3....0..2..0..2..0....0..0..0..0..2
..1..0..2..2..0....0..1..3..3..1....0..1..3..2..2....2..0..1..0..2
		

Formula

Empirical: a(n) = 78*a(n-1) -1043*a(n-2) +2012*a(n-3) +10236*a(n-4) -39726*a(n-5) +41724*a(n-6) -6408*a(n-7) -8680*a(n-8) +2592*a(n-9) -96*a(n-10)

A232953 Number of nX6 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

243, 27771, 3484893, 442227825, 56282275743, 7168373617095, 913176469752921, 116335186551225981, 14820857088037937067, 1888152565941258630963, 240547722416361692415285, 30645415985954670300604329
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Comments

Column 6 of A232955

Examples

			Some solutions for n=2
..0..0..1..3..2..2....0..0..2..3..3..3....0..1..0..0..0..0....0..1..1..1..3..1
..1..1..1..3..2..0....0..0..2..3..1..3....0..2..0..0..1..0....1..0..0..1..1..3
		

Formula

Empirical: a(n) = 164*a(n-1) -4626*a(n-2) -10237*a(n-3) +724806*a(n-4) -2489128*a(n-5) -20967827*a(n-6) +129949639*a(n-7) -92364571*a(n-8) -632285585*a(n-9) +1013530592*a(n-10) +686481298*a(n-11) -1825492832*a(n-12) +98427893*a(n-13) +965164167*a(n-14) -223865096*a(n-15) -150502642*a(n-16) +39404908*a(n-17) +4977174*a(n-18) -881024*a(n-19) -36192*a(n-20) +4272*a(n-21)

A232954 Number of nX7 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

729, 166629, 42904365, 11228712351, 2953363127697, 777971521023633, 205030957086979647, 54043267342289534097, 14245737532796759368533, 3755217033315506600279775, 989890841378547325619047929
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Comments

Column 7 of A232955

Examples

			Some solutions for n=2
..0..2..0..2..3..2..2....0..2..0..1..1..3..3....0..0..1..3..2..3..2
..2..0..0..1..0..2..3....3..2..0..0..1..3..1....0..1..1..3..2..2..2
		

A232956 Number of 2 X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

4, 21, 129, 771, 4629, 27771, 166629, 999771, 5998629, 35991771, 215950629, 1295703771, 7774222629, 46645335771, 279872014629, 1679232087771, 10075392526629, 60452355159771, 362714130958629, 2176284785751771
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Examples

			Some solutions for n=5:
..0..1..0..2..3....0..0..0..0..1....0..0..0..1..0....0..1..1..1..0
..3..2..0..2..2....0..1..1..0..2....0..0..1..1..0....0..0..0..1..0
		

Crossrefs

Row 2 of A232955.

Formula

Empirical: a(n) = 5*a(n-1) + 6*a(n-2).
Conjectures from Colin Barker, Oct 06 2018: (Start)
G.f.: x*(4 + x) / ((1 + x)*(1 - 6*x)).
a(n) = (25*6^n - 18) / 42 for n even.
a(n) = (25*6^n + 18) / 42 for n odd.
(End)

A232957 Number of 3 X n 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

16, 147, 1881, 22971, 283131, 3484893, 42904365, 528197043, 6502696923, 80055386493, 985570487037, 12133464037491, 149376378762507, 1838988638568957, 22639986598509837, 278723306070050355
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Examples

			Some solutions for n=4:
..0..0..1..1....0..0..0..0....0..1..0..0....0..1..1..1....0..1..1..1
..0..1..1..0....1..1..1..1....0..1..1..0....3..1..1..3....0..0..0..1
..0..0..0..1....1..0..1..0....0..0..1..1....3..1..3..1....1..1..1..0
		

Crossrefs

Row 3 of A232955.

Formula

Empirical: a(n) = 12*a(n-1) + 7*a(n-2) - 40*a(n-3) + 12*a(n-4).
Empirical g.f.: x*(16 - 45*x + 5*x^2 + 10*x^3) / (1 - 12*x - 7*x^2 + 40*x^3 - 12*x^4). - Colin Barker, Oct 06 2018

A232958 Number of 4Xn 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

64, 1029, 27441, 685251, 17429409, 442227825, 11228712351, 285082486341, 7238105184837, 183771148650939, 4665845904118053, 118463173683294573, 3007712801760687567, 76364121654785540601, 1938841730920089921489
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Comments

Row 4 of A232955

Examples

			Some solutions for n=3
..0..1..0....0..1..0....0..2..0....0..0..0....0..1..3....0..2..0....0..1..1
..0..1..3....3..2..0....2..0..2....2..2..0....3..1..0....3..2..0....1..1..3
..0..2..3....0..2..2....2..2..2....3..2..3....0..2..3....3..2..0....3..1..0
..3..2..0....0..2..3....2..3..3....0..1..0....3..1..3....3..1..0....3..2..3
		

Formula

Empirical: a(n) = 24*a(n-1) +76*a(n-2) -1008*a(n-3) -992*a(n-4) +8762*a(n-5) -7403*a(n-6) -2174*a(n-7) +3324*a(n-8) -416*a(n-9) -96*a(n-10)

A232959 Number of 5Xn 0..3 arrays with no element x(i,j) adjacent to value 3-x(i,j) horizontally, diagonally or antidiagonally, and top left element zero.

Original entry on oeis.org

256, 7203, 400329, 20442651, 1074244299, 56282275743, 2953363127697, 154964050219677, 8131839344628711, 426724728385684671, 22392882542866505109, 1175093728648087275513, 61664507065517646615231
Offset: 1

Views

Author

R. H. Hardin, Dec 02 2013

Keywords

Comments

Row 5 of A232955

Examples

			Some solutions for n=2
..0..0....0..1....0..2....0..1....0..1....0..1....0..0....0..0....0..1....0..0
..1..0....0..0....3..2....3..1....1..0....0..2....0..2....1..1....3..2....2..2
..2..3....2..2....0..1....3..3....2..0....3..2....2..0....0..0....2..3....2..2
..2..0....2..2....0..1....1..3....1..3....2..2....2..2....0..0....1..0....2..2
..2..2....2..2....3..2....3..1....1..3....2..2....3..3....2..0....0..0....2..0
		

Formula

Empirical: a(n) = 67*a(n-1) -533*a(n-2) -15660*a(n-3) +183231*a(n-4) +657345*a(n-5) -14397321*a(n-6) +26479475*a(n-7) +308726752*a(n-8) -1394230594*a(n-9) -93496336*a(n-10) +10567010405*a(n-11) -15260787758*a(n-12) -20784722042*a(n-13) +61450333950*a(n-14) -11848262788*a(n-15) -72270718040*a(n-16) +48716606000*a(n-17) +23916567320*a(n-18) -26795989184*a(n-19) -10634656*a(n-20) +4071926912*a(n-21) -391701632*a(n-22) -188446976*a(n-23) +19444224*a(n-24) +1963008*a(n-25) -110592*a(n-26) for n>27
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